One conventional process for the deposition of superconducting thick films, such as YBCO, and other industrial films such as semi-conductor films, ferroelectric films, insulating or optical coating films, and the like, is pulsed laser deposition (PLD). In such a process, a target, typically a disk-like shaped target, of the material or materials to be deposited is contacted with a laser beam of the desired energy and frequency. Commonly, such a disk-like target is rotated during the process to avoid contacting only a single spot of the target. In some PLD processes, a laser beam is simply rastered across sections of a target so that it is the laser beam that is moved rather than the target.
Since initial development, coated conductor research on HTS superconductors has focused on fabricating increasing lengths of the material, while increasing the overall critical current carrying capacity. Different research groups have developed several techniques of fabricating coated conductors. Regardless of which techniques are used for the coated conductors, the goal of obtaining highly textured superconducting thick films, such as YBa2Cu3O7-x (YBCO), with high supercurrent carrying capability on metal substrates remains. The use of thick superconducting films for coated conductors appears logical because both the total critical current and the engineering critical current density (defined as the ratio of total critical current and the cross-sectional area of the tape) are directly correlated with the thickness of the superconducting films.
Multilayer HTS films have recently been shown to yield high current superconducting composites because high quality, thick HTS coatings can be grown with multilayers.
U.S. Pat. Nos. 5,356,522 and 5,580,667 by Lai et al. describe the use of sectored targets in the preparation of thin film magnetic disks. Their sectored targets are designed for deposition via sputtering as the target moves consecutively linearly through successive regions of the sputtering system. They do not describe sectored disks, do not describe rotation of sectored targets during deposition, and do not describe deposition of high temperature superconducting materials.